WO2006044762A2 - Tetrahydro-5h-pyrimido[4,5-d]azepine derivatives useful for the treatment of diseases associated with the 5-ht2c receptor - Google Patents

Abstract

The invention relates to tetrahydro-5H-pyrimido[4,5-d]azepine compounds of Formula (I) that are useful in the treatment or prevention of diseases and/or behaviors that involve the 5-HT2C receptor. The compounds of the present invention may also be used for the treatment or prevention of diseases and/or disorders including obesity, obesity-related disorders such as diabetes, feeding behavior disorders, eating disorders such as bulimia and anorexia nervosa, and premenstrual tension.

Description

TETRAHYDRO-5H-PYRIMIDO[4,5-d]AZEPINE DERIVATIVES USEFUL FOR THE TREATMENT OF DISEASES ASSOCIATED WITH THE 5-HT_2C RECEPTOR

FIELD OF THE INVENTION

[001] This application claims benefit of U.S. Provisional Application Serial No. 60/619,195; filed on October 15, 2004, the contents of which are incorporated herein by reference in their entirety.

[002] The invention relates to tetrahydro-5H -pyrimido[4,5-d]azepine compounds of Formula (I) that are useful in the treatment or prevention of diseases and/or behaviors that involve the 5-HT_2C receptor. The compounds of the present invention may also be used for the treatment or prevention of diseases and/or disorders including obesity, obesity-related disorders such as diabetes, feeding behavior disorders, eating disorders such as bulimia and anorexia nervosa, and premenstrual tension.

BACKGROUND OF THE INVENTION

[003] Obesity, which is an excess of body fat relative to lean body mass, is a chronic disease that is highly prevalent in modem society. It is associated not only with a social stigma, but also with decreased life span and numerous medical problems, including adverse psychological development, coronary artery disease, hypertension, stroke, diabetes, hyperlipidaemia, and some cancers (see, e.g., Nishina, et al., Metab. 43:554- 558, 1994; Grundy and Barnett, Dis. Mon. 36:641-731 , 1990; Rissanen, et al., British Medical Journal, 301 :835-837, 1990).

[004] Obesity is considered a major medical problem largely because it is a factor for a number of other diseases. For example, obesity is correlated with a much higher incidence of type 2 diabetes (non-insulin dependent diabetes mellitus, NIDDM), hypertension, hyperlipidemia, myocardial infarction, cancers, gallbladder disease, respiratory disease, gout, arthritis, and dermatological disease. In addition, obese individuals have a higher incidence of mortality at a younger age as compared to their leaner counterparts.

[005] Serotonin (5-HT) has been implicated in the regulation of feeding behavior. Drugs which increase the concentration of 5-HT in the synaptic cleft by increasing 5-HT release and/or inhibiting re-uptake of the transmitter (such as Redux® (dexfenfluramine) and sibutramine) are effective long-term treatments for obesity, albeit with significant side-effects.

[006] Serotonin produces physiological effects by acting on a heterogeneous family of receptors. The lack of selective agonists and antagonists for the individual subtypes of serotonin receptors has prevented a complete characterization of the physiological role of each receptor subtype.

[007] Regulation of several subtypes of 5-HT receptors (5-HT_1A, 5-HT_1B, 5-HT_2A, 5-HT_2B, 5-HT₆, and 5-HT_2C) has been demonstrated to elicit effects on food intake. For example, activation of both 5-HT_2A and 5-HT_2C receptors decrease food intake. However, while 5- HT_2A receptor agonists are thought to decrease food intake by disrupting the ability of the animal to feed, the 5-HT_2C receptor has been implicated in the regulation of satiety. 5- HT_2C receptors are localized to the hypothalamus and the brainstem, two brain regions known to play a critical role in the modulation of food intake. Furthermore, data available to date suggests that 5-HT_2C receptor agonists produce a decrease in food intake which is associated with the least likely potential for side effects.

[008] Targeting the 5-HT_2C receptor for the treatment of obesity and feeding disorders has previously been described (Kennett & Curzon, Psychopharmacology 96(1):93-100, 1988; Curzon, Adv. Exp. Med. Biol. 294:377-88, 1991 ; Walsh, et al., Psychopharmacology 16(1 ):120-2, 1994; Dourish, Obes. Res. Suppl. 4:449-462, 1995; Sargent, et al., Psychopharmacology 133:309-312,1997). It would be expected that agonists that are selective for this receptor would have superior properties with respect to other known appetite suppressants, such as serotonin/noradrenaline re-uptake inhibitors and/or releasers, which can lead to hypertension and/or cardiac valve defects.

[009] Non-selective agonists/partial agonists (e.g., mCPP, TFMPP) of the 5-HT_2C receptor have been shown to reduce food intake in rats and to accelerate the appearance of the behavioral satiety sequence. Importantly, the hypophagic effects of mCPP are antagonized by the selective 5-HT_2C receptor antagonist, SB-242084. Recent findings from studies in normal human volunteers and obese subjects administered mCPP have also shown decreases in food intake. A single injection of mCPP decreased food intake in female volunteers and subchronic treatment for a 14 day period decreased the appetite and body weight of obese male and female subjects.

[010] The importance of the 5-HT_2C receptor in mediating feeding behavior is further supported by studies on mutant 5-HT_2C-knockout mice (Tecott, et al., Nature 374:542- 546, 1995; Heath & Hen, Curr. Biol. 5(9):997-999, 1995). Interestingly, the knockout mice show significantly greater weight gain and adipose tissue deposits over time compared to wild-type mice. Additional studies have confirmed that 5-HT_2C knockout mice overeat and become obese which appears to be due to a defect in their satiety mechanism. In the behavioral satiety sequence model, knockout animals continued to eat for a significantly longer period of time than the wild-type controls. The prolonged eating in the 5-HT_2C receptor knockout mice was enhanced by access to a sweet diet, suggesting that the 5- HT_2C receptor may also play a role in palatability.

[011] It is significant that the decrease in food intake induced by dexfenfluramine is markedly attenuated in 5-HT_2C receptor knockout mice. These results suggest that dexfenfluramine enhances satiety and decreases food intake via an agonist action on 5- HT_2C receptors. In addition, in wild-type animals, these anorectic effects of dexfenfluramine are blocked by the 5-HT_2C-selective antagonist, SB-242084. These data are consistent with the clinical evidence that the anorectic effect of dexfenfluramine was blocked by the 5HT₂ receptor antagonist, ritanserin.

[012] Thus, animal and human data strongly implicate the involvement of the 5-HT_2C receptor in satiety, and compounds that interact with this receptor would be effective in treating diseases and/or disorders such as obesity, eating disorders, and the like.

[013] The compounds of the present invention interact with the 5-HT_2C receptor. Thus, these compounds may be useful for treatment or prevention of diseases and/or behaviors associated with the 5-HT_2C receptor. Furthermore, the compounds of the present invention may also be used for the treatment and/or prevention of obesity, obesity-related disorders such as diabetes, feeding behavior, eating disorders such as bulimia and anorexia nervosa, and premenstrual tension. In addition, other diseases and/or disorders such as central nervous disorders, depression, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction, and chronic fatigue syndrome may also be treated and/or prevented by the compounds of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[014] The invention relates to a compound of Formula (I)

wherein R¹ is

• (C₁-C₄)alkyl,

• phenyl optionally substituted with halo, or

• (C₃-C₆) cycloalky I optionally substituted with (C₁-C₃)alkyl;

R² is

• C₁-C₆ alkyl,

• halo

• piperidin-1-yl

• pyrrolidin-1-yl

• phenylpyrrolidin-1 -yl optionally substituted on the phenyl ring with up to two groups selected from halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃,

• phenylpiperidin-1-yl optionally substituted on the phenyl ring with up to two groups selected fromhalo or CF₃,

• phenoxypiperidin-1 -yl optionally substituted on the phenyl ring with up to two groups selected from halo or CF₃,

• phenylpiperazin-1 -yl optionally substituted on the phenyl ring with up to two groups selected from (C₁-C₃)alkyl, halo, CF₃, or (C₁-C₃)alkoxy,

• -NR⁵R⁶ wherein

R⁵ is H or (C₁-C₃)alkyl, and

R⁶ is (C₁-C₃)alkyl optionally substituted with

• indoly-2-yl optionally substituted with halo,

• phenyl optionally substituted with up to two groups selected from (C₁-C₃)alkoxy, or benzodioxan-6-yl, or

• OR⁷ wherein

R⁷ is

• H₁

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl,

• 2,3-dihydro-inden-2-yl,

• tetrahydrofuran-yl, or

• (C₁-C₆)alkyl optionally substituted with

• F up to the perfluoro level,

• (C₃-C₆)cycloalkyl,

• (C₁-C₃)alkoxy,

• — N[(C₁-C₃)alkyl]₂, . — NH[(C₁-C₃)alkyl],

• morpholin-1-yl,

• phenyl optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, NO₂, (C₁-C₃)alkoxy, or N[(C₁-C₃)alkyl]₂,

• 2,3-dihydro-benzo[1 ,4]dioxin-2-yl,

• 2,3-dihydro-1 H-indol-2-yl,

• tetrahydrofuran-yl,

• 2-oxo-2,3-dihydro-benzoimidazol-1 -yl,

• 2-oxo-pyrrolidin-1-yl, or

• — N[(C₁-C₃)alkyl]phenyl, wherein the phenyl is optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, (C₁- C₃)alkoxy, and — N[(C₁-C₃)alkyl]₂;

R³ is H or (C₁-C₃)alkyl; and

R⁴ is H, methyl, -C(O)O-R⁸, or -C(O)R⁹; wherein

R⁸ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃, and

R⁹ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃;

or pharmaceutically acceptable salts thereof.

Definitions

[015] The terms identified above have the following meaning throughout:

[016] The terms "(C₁-C₃)alkyl," "(C₁-C₄)alkyl," and (C₁-C₆)alkyl" mean a linear or branched saturated hydrocarbon groups having from 1 to about 3, from 1 to about 4, and from 1 to about 6 carbon atoms, respectively. Such groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, and the like.

[017] The term "(C₁-C₃)alkoxy" means a linear or branched saturated hydrocarbon group having from about 1 to about 3 carbon atoms, said group being attached to an oxygen atom. The oxygen atom is the atom through which the alkoxy substituent is attached to the rest of the molecule. Such groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, and the like.

[018] The term "halo" means F, Br, Cl, and I.

[019] The term "(C₃-C₆)cycloalkyl" means a saturated monocyclic alkyl group of from 3 to about 6 carbon atoms and includes, but is not limited to, such groups as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[020] The term "optionally substituted" means that the moiety so modified may be unsubstituted or substituted with the identified substituent(s). When any moiety is described as being substituted, it can have one or more of the indicated substituents that may be located at any available position on the moiety. When there are two or more substituents on any moiety, each substituent may be defined independently of any other substituent and may, accordingly, be the same or different.

[021] Each substituent may replace any H atom on the moiety so modified as long as the replacement is chemically possible and chemically stable. When there are two or more substituents on any moiety, each substituent is chosen independently of any other substituent and can, accordingly, be the same or different.

[022] The compounds of Formula (I) may contain one or more asymmetric centers, depending upon the location and nature of the various substituents desired. Asymmetric carbon atoms may be present in the (R) or (S) configuration. Preferred isomers are those with the absolute configuration which produces the compound of Formula (I) with the more desirable biological activity. In certain instances, asymmetry may also be present due to restricted rotation about a given bond, for example, the central bond adjoining two aromatic rings of the specified compounds.

[023] Substituents on a ring may also be present in either cis or trans form, and a substituent on a double bond may be present in either Z or E form.

[024] It is intended that all isomers (including enantiomers arid diastereomers), either by nature of asymmetric centers or by restricted rotation as described above, as separated, pure or partially purified isomers or racemic mixtures thereof, be included within the scope of the instant invention. The purification of said isomers and the separation of said isomeric mixtures may be accomplished by standard techniques known in the art.

[025] Representative salts of the compounds of Formula (I) include the conventional non-toxic salts and the quaternary ammonium salts which are formed, for example, from inorganic or organic acids or bases by means well known in the art. For example, such acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cinnamate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, itaconate, lactate, maleate, mandelate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oxalate, pamoate, pectinate persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, sulfonate, tartrate, thiocyanate, tosylate, and undecanoate.

[026] Base salts include alkali metal salts such as potassium and sodium salts, alkaline earth metal salts such as calcium and magnesium salts, and ammonium salts with organic bases such as dicyclohexylamine salts and N-methyl-D-glucamine. Additionally, basic nitrogen containing groups may be quaternized with such agents as lower alkyl halides such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl, diethyl, and dibutyl sulfate and diamyl sulfates; long chain halides such as decyl, lauryl, myristyl and strearyl chlorides, bromides, and iodides; aralkyl halides like benzyl and phenethyl bromides and others.

[027] The esters in the present invention are non-toxic, pharmaceutically acceptable ester derivatives of the compounds of Formula (I). This may include, for example, ester derivatives prepared from acetic, benzoic, mandelic, stearic, lactic, salicylic, hydroxynaphthoic, glucoheptonic, and gluconic acid. The compounds of Formula (I) may be esterified by a variety of conventional procedures well known by those skilled in the art. For example, esterification may be reached using the appropriate carboxylic acid in the presence of trifluoroacetic anhydride and optionally, pyridine, or in the presence of Λ/,Λ/-carbonyldiimidazole with pyridine. One skilled in the art would readily know how to successfully carry out these as well as other methods of esterification. Sensitive or reactive groups on the compound of Formula (I) may need to be protected during any of the above methods for forming esters, and protecting groups may be added and removed by conventional methods well known in the art.

[028] Another object of this invention is to provide methods of making the compounds of the invention. The compounds may be prepared from readily available materials by the methods outlined in the Reaction Schemes and Examples below, and by obvious modifications thereto.

[029] The particular method to be utilized in the preparation of the compounds of this invention depends upon the specific compound desired. Such factors as the selection of the specific moieties and the specific substituents on the various moieties, all play a role in the path to be followed in the preparation of the specific compounds of this invention. These factors are readily recognized by one of ordinary skill in the art.

[030] For synthesis of any particular compound, one skilled in the art will recognize that the use of protecting groups may be required for the synthesis of compounds containing certain substituents. A description of suitable protecting groups and appropriate methods of adding and removing such groups may be found in the art (see, e.g., T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis; Wiley: New York, 1999).

[031] In the Reaction Schemes below, one skilled in the art will recognize that reagents and solvents actually used may be selected from several reagents and solvents well known in the art to be effective equivalents. When specific reagents or solvents are shown in a reaction scheme, therefore, they are meant to be illustrative examples of conditions desirable for the execution of that particular reaction scheme. Abbreviations not identified in accompanying text are listed later in this disclosure under "Abbreviations and Acronyms."

General Methods of Preparation

[032] Compounds of Formula (I) may be prepared by standard means or methods analogous thereto, from starting materials which are either commercially available or prepared by standard means obvious to those skilled in the art. Unless otherwise specified, R¹-R⁴ have the same meanings as described above for Formula (I).

[033] Reaction Scheme 1

[034] For example, compounds of Formula (I), where R is bonded to the pyrimidine ring with a heteroatom such as oxygen or nitrogen, may be synthesized by the method illustrated in Reaction Scheme 1. In this scheme, condensation of a β-ketoester of Formula (II) with a carbamidine of Formula (III) provides the fused pyrimidine azepine of Formula (IV). Treatment of Formula (IV) with a chlorinating agent, such as phosphorus oxychloride, provides the pyrimidinyl chloride of Formula (V). R⁴ may be labile under the reaction conditions for chlorination, and reinstallation of R⁴ may be necessary. That is, in Formula (V), when R⁴ is equal to hydrogen, it can be treated with a compound of the Formula R⁴ - Ig (where Ig is a leaving group such as iodo, bromo, chloro, or carbonate) in the optional presence of a base to provide the corresponding Formula (V) compound where R⁴ is other than hydrogen.

[035] A compound of Formula H-R², in the presence of a base such as potassium tert- butoxide or triethylamine, is allowed to react with the chloro compound of Formula (V) in a nucleophilic substitution reaction to provide the compound of Formula (I).

[036] In addition, compounds of Formula (I) where R² is bonded to the pyrimidine ring with a carbon atom may also be prepared from the chloride of Formula (V) as outlined in Reaction Scheme I. A compound of Formula (V) can be treated with a compound of Formula BrMg - R² in the presence of an iron (III) catalyst, such as iron(lll) acetylacetonate to provide a compound of Formula (I) where R² is an alkyl group.

[037] Salts (for example, a hydrochloride or a fumaric acid salt) of the compounds of Formula (I) may be prepared by stirring compounds of Formula (I) in an ethereal solution with a protic acid such as hydrochloric acid or fumaric acid.

[038] Alternatively, R⁴ of Formula (Ib) [(l)a, where R⁴ is hydrogen] may be converted from hydrogen to a group other than hydrogen as shown in Reaction Scheme 2. A compound of Formula (Ib) where R⁴ is hydrogen may be treated with a base, such as sodium bicarbonate, to provide a compound of Formula (Ic) where R⁴ is hydrogen. The compound of Formula (Ic) where R⁴ is hydrogen may then undergo reaction with a compound of Formula R⁴ - Ig (where Ig is a leaving group such as iodo, bromo, chloro, or carbonate), in the optional presence of a base, to provide compounds of Formula (Id) where R⁴ is other than hydrogen.

[039] Reaction Scheme 2

[040] Compounds of Formula (II) are either commercially available or are readily available by the synthetic sequences described in Reaction Scheme 3 and Reaction Scheme 4.

[041] Reaction Scheme 3

[042] For example, the compound of Formula (II) where one R³ is 3-methyl may be prepared from the beta-alanine derivative (Vl). This compound of Formula (VI) can be deprotonated with a base, such as sodium hydride, and allowed to react with an alkylating agent of Formula (VII) to yield a compound of Formula (VIII). The α,β-unsaturated ester of Formula (VIII) may then undergo a tandem reduction and cyclization in the presence of an electron transfer source such as magnesium, and in an alcoholic solvent such as methanol to provide the compound of Formula (Ha). Alternatively, the process may be completed in stepwise fashion by treating the compound of Formula (VIII) with a reducing agent, such as sodium borohydride, to give the diester of Formula (IX). The compound of Formula (IX) can then undergo a Dieckmann condensation when treated with a base such as sodium methoxide, to generate the compound of Formula (Ha).

[043] Compounds of Formula (II) in which one R³ group is 6-methyl or two R³ groups are 6,6-dimethyl can be prepared as shown in Reaction Scheme 4.

[044] Reaction Scheme 4

[045] example, the ketoester of Formula (lib), wherein the R³ at position 3 can be either a hydrogen or a 3-methyl group, may be methylated to give the compound of Formula (lie) by quenching the dianion of Formula (lib), formed by treatment of Formula (lib) with strong base, with a methylating agent such as methyl iodide. The dimethyl compound of Formula (lid) is likewise formed by quenching the dianion of (lie) with methyl iodide.

[046] By using these above described methods, the compounds of the invention may be prepared. The following specific examples are presented to further illustrate the invention described herein, but they should not be construed as limiting the scope of the invention in any way. EXPERIMENTAL EXAMPLES OF THE INVENTION General Experimental Procedures

[047] HPLC-electrospray mass spectra (HPLC ES-MS) were obtained using a Hewlett Packard 1100 HPLC equipped with a quaternary pump, a variable wavelength detector, a YMC Pro 18 2.0 mm x 23 mm column, and a Finnigan LCQ ion trap mass spectrometer with electrospray ionization. Gradient elution from 90% A to 95% B over 5 minutes was used on the HPLC. Buffer A was 98% water, 2% Acetonitrile, and 0.02% TFA, and Buffer B was 98% Acetonitrile, 2% water, and 0.018% TFA. Spectra were scanned from 140- 1200 amu using a variable ion time according to the number of ions in the source.

[048] Proton (¹H) nuclear magnetic resonance (NMR) spectra were measured with a General Electric G N-Omega 300 (300 MHz) spectrometer with either Me₄Si (δ 0.00) or residual protonated solvent (CHCI₃ δ 7.26; MeOH δ 3.30; DMSO δ 2.49) as standard.

Abbreviations and Acronyms

[049] When the following are used throughout the disclosure, they have the following meaning:

Biotage® silica gel chromatographic system, Biotage Inc.

BOC tert-butoxycarbonyl n-BuLi n-butyllithium calcd calculated

Cbz carbobenzyloxy

CDI carbonyl diimidazole

CD₃OD methanol-d₄

Celite® diatomaceous earth filter agent, Celite Corp. cone concentrated d doublet

DMF N,N-dimethy[formamide

DMSO dimethylsulfoxide

DMSO-d₆ dimethylsulfoxide-d₆

ES-MS electrospray mass spectroscopy h hour, hours

¹H NMR proton nuclear magnetic resonance

HPLC high performance liquid chromatography

J coupling constant (NMR spectroscopy)

LC liquid chromatography

LC-MS liquid chromatography-mass spectrometry m multiplet

M molar

MeCN acetonitrile

MeOH methanol

Me₄Si tetramethylsilane min minute, minutes

MS mass spectrum, mass spectrometry m/z mass-to-charge ratio

N normal

NMP N-methylpyrrolidine

PS-DIEA polystyrene-bound diisopropylethylamine

Rf retention factor (TLC)

RT retention time (HPLC) rt room temperature s singlet t triplet

THF tetrahydrofuran

TFA trifluoroacetic acid

TLC thin layer chromatography v/v volume per volume w/v weight per volume w/w weight per weight.

[050] The compounds described in the Examples are intended to be representative of the invention, and it will be understood that the scope of the invention is not limited by the scope of the examples. Those skilled in the art will recognize that the invention may be practiced with variations on the disclosed structures, materials, compositions and methods, and such variations are regarded as within the ambit of the invention.

[051] Example 1

Preparation of tert-butyl 2-cvclopropyl-4-(3,3,3-trifluoropropoxyl-5,6,8,9-tetrahydro- 7H-pyrimido[4,5-d]azepine-7-carboxylate

[052] Step 1 : Preparation of tert-butyl 2-cvclopropyl-4-hvdroxy-5,6,8,9-tetrahydro-7H - pyrimido[4,5-d]azepine-7-carboxylate

[053] Commercially available 1- tert-butyl 4-ethyl 5-oxoazepane-1 ,4-dicarboxylate (6.0 g, 21.0 mmol) and cyclopropanecarboximidamide hydrochloride (2.54 g, 21.0 mmol) were combined and dissolved in ethyl alcohol (21 mL ). Sodium ethoxide (21 weight % solution in ethyl alcohol) (7.85 mL , 21.0 mmol) was added, and the mixture was heated at 80°C for 2 h. The contents of the reaction flask were cooled to 0°C and filtered. The solids were washed with cold methanol and dried in a 40°C vacuum oven to provide the title compound as an off-white solid (4.6 g, 72%). ¹H NMR (300 MHz, DMSO-d₆) δ 12.55 (s, 1 H), 3.46-3.36 (m, 4 H), 2.71-2.63 (m, 4 H), 1.88-1.79 (m, 1 H), 1.38 (s, 9 H), 0.95-0.93 (m, 4 H); ES-MS m/z 306.2 [M+ H⁺]; HPLC RT (min) 2.34. [054] Step 2: Preparation of tert-butyl 4-chloro-2-cvclopropyl-5,6,8,9-tetrahydro-7H - pyrimidof4,5-cnazepine-7-carboxylate

[055] tert-Butyl 2-cyclopropyl-4-hydroxy-5,6,8,9-tetrahydro-7H-pyrimido[4,5-d]azepine-7- carboxylate (4.61 g, 15.1 mmol) was dissolved in phosphorus oxychloride (14 mL) and heated to 90°C. Λ/,Λ/-Dimethylaniline (1.91 mL, 15.1 mmol) was added, and heating was continued for 1 h. The solution was cooled to rt, poured onto ice, and stirred for 3 h. The aqueous mixture was treated with 5N aqueous sodium hydroxide solution until the mixture reached a stable pH 10. The basic solution was extracted with chloroform / isopropyl alcohol (4:1) (3x). The organic extracts were combined, dried (MgSO₄), and concentrated under reduced pressure. The resulting crude orange oil was purified by flash chromatography on silica gel eluted first with 1 :1 hexanes / ethyl acetate followed by 10% 2M solution of ammonia in methanol / 90% 1 :1 hexanes / ethyl acetate. Fractions containing the chloride were combined and concentrated under reduced pressure. The chloride was dissolved in anhydrous tetrahydrofuran and stirred with di-tert-butyl- dicarbonate (3.29 g, 15.1 mmol) for 1 h. The reaction mixture was concentrated under reduced pressure to remove solvent and was purified by flash chromatography on silica gel eluted with 9:1 hexanes / ethyl acetate. The title compound was collected as a pale yellow oil that crystallized upon standing (3.3 g, 67%). ¹H NMR (300 MHz, CDCI₃) δ 3.62- 3.57 (m, 4 H), 3.09-3.04 (m, 4 H), 2.18-2.10 (m, 1 H), 1.48 (s, 9 H), 1.13-1.00 (m, 4 H); ES-MS m/z 324.1 [M+H⁺]; HPLC RT (min) 3.46.

[056] Step 3: Preparation of tert-butyl 2-cvclopropyl-4-(3,3,3-trifluoropropoxy)-5,6,8,9- tetrahydro-7H-pyrimido[4,5-d]azepine-7-carboxylate

[057] 3,3,3-Trifluoropropan-1-ol (0.43 g, 3.7 mmol) was dissolved in 1 ,4-dioxane (5 mL). Potassium tert-butoxide (572 mg, 5.1 mmol) was added, and the mixture was stirred at rt for 15 min. tert-Butyl 4-chloro-2-cyclopropyl-5,6,8,9-tetrahydro-7H-pyrimido[4,5- d]azepine-7-carboxylate (1.1 g, 3.4 mmol) was then added as a solution in 1 ,4-dioxane (5 ml_). The mixture was heated at 50°C overnight. The resulting white suspension was concentrated under reduced pressure, and the residue was partitioned between water and ethyl acetate. The organic layer was separated, dried (MgSO₄), and concentrated under reduced pressure to give the title compound as a colorless oil (1.2 g, 94%). ¹H NMR (300 MHz, CD₃OD) δ 4.56 (t, 2 H), 3.64-3.48 (m, 4 H), 3.05-3.01 (m, 2 H), 2.90-2.86 (m, 2 H), 2.76-2.61 (m, 2 H), 2.11-2.01 (m, 1 H), 1.45 (s, 9 H), 1.09-0.97 (m, 4 H); LC-MS m/z 402.0 [M+H⁺]; HPLC RT (min) 2.69.

[058] Example 2

Preparation of 2-cvclopropyl-4-(3,3,3-trifluoropropoxy)-6,7,8,9-tetrahvdro-5H- pyrimido[4,5-d]azepine dihvdrochloride

[059] tert-Butyl 2-cyclopropyl-4-(3,3,3-trifluoropropoxy)-5,6,8,9-tetrahydro-7H- pyrimido[4,5-d]azepine-7-carboxylate (Example 1 , 1.2 g, 3.0 mmol) was dissolved in 1 ,4- dioxane (3 mL) and treated with a solution of 4N HCI in 1 ,4-dioxane (3.4 mL, 13.6 mmol). The mixture was stirred at rt overnight resulting in a white suspension. The product was collected by filtration to provide the title compound as a white solid (0.80 g, 59%). ¹H NMR (300 MHz,CD₃OD) δ 4.77 (t, 2 H), 3.58-3.53 (m, 2 H), 3.49-3.41 (m, 4 H), 3.25-3.21 (m, 2 H), 2.88-2.73 (m, 2 H), 2.37-2.30 (m, 1 H), 1.47-1.42 (m, 4 H); LC-MS m/z 302.3 [M+H⁺]; HPLC RT (min) 1.64.

[060] Example 3

Preparation of 2-cyclopropyl-4-propyl-6,7,8,9-tetrahydro-5H-pyrimido[4,5-d]azepine hydrochloride

[061] tert-Butyl 4-Ghloro-2-cyclopropyl-5,6,8,9-tetrahyclro-7H-pyrimiclo[4,5-d]azepine-7- carboxylate (70 mg, 0.22 mmol) was dissolved in a solution of 10:1 THF:NMP. The solution was degassed and purged with nitrogen twice before adding iron(III) acetylacetonate (4 mg, 0.011 mmol). The reaction solution was then slowly treated with N-propylmagnesium bromide (160 μl_, 0.32 mmol). After 20 min, the reaction was diluted with diethyl ether and water. The organic layer was separated, dried over MgSO₄, and concentrated to an amber oil that analyzed as tert-butyl 2-cyclopropyl-4-propyl-5, 6,8,9- tetrahydro-7H-pyrimido[4,5-d]azepine-7-carboxylate. ¹H NMR (300 MHz, CD₃OD) δ 3.64- 3.54 (m, 4 H), 3.07-3.03 (m, 2 H), 2.96-2.92 (m, 2 H), 2.76-2.71 (m, 2 H), 2.12-2.03 (m, 1 H), 1.72-1.59 (m, 2 H), 1.42 (bs, 9 H), 1.18-0.95 (m, 7 H); LC-MS m/z 332.2 [M+H⁺]; HPLC RT (min) 2.92.

[062] tert-Butyl 2-cyclopropyl-4-propyl-5,6,8,9-tetrahydro-7H-pyrimido[4,5-d]azepine-7- carboxylate was dissolved in 1 ,4-dioxane (1 mL) and treated with a solution of 4N HCI in 1 ,4-dioxane (1 mL) and stirred at rt until TLC indicated all starting material had been consumed. The reaction mixture was concentrated under reduced pressure. The resulting oil was taken up in acetonitrile and concentrated by rotary evaporation until a solid was obtained. The solids were collected by filtration and rinsed with acetonitrile to give 41 mg of the title compound as a tan solid (57%). ¹H NMR (300 MHz, CD₃OD) δ 3.48-3.41 (m, 4 H), 3.36-3.32 (m, 4 H), 3.02-2.97 (m, 2 H), 2.42-2.33 (m, 1 H), 1.87-1.68 (m, 2 H), 1.44-1.38 (m, 4 H), 1.08 (t, 3 H); LC-MS m/z232.3 [M+H⁺]; HPLC RT (min) 0.35.

[063] Example 4

Preparation of 2-cvclopropyl-9-methyl-4-(3,3,3-trifluoropropoxy)-6,7,8,9- tetrahvdro-5H-pyrimido[4,5-d]azepine dihydrochloride

[064] Step 1 : Preparation of 1-tert-butyl 4-ethyl 6-methyl-5-oxoazepane-1 ,4- dicarboxylate

[065] Sodium hydride, 95% (186 mg, 7.36 mmol) was suspended in THF (10 ml_). The suspension was cooled to 0°C, and 1- tert-butyl 4-ethyl-5-oxoazepane-1 ,4-dicarboxylate (1.0 g, 3.5 mmol) in THF (5 mL ) was added. The mixture was allowed to warm to rt and was stirred for an additional 30 min. The contents of the flask were cooled to -78°C, and n-BuLi (1.4 ml_, 3.5 mmol) was added dropwise. Once the addition was complete, the solution was stirred for another 10 min at -78°C. lodomethane (240 μL, 3.85 mmol) was added, and the mixture was allowed to return to rt. An excess of water was added, and the mixture was extracted with ethyl acetate. The organic layer was separated, dried over anhydrous sodium sulfate, and concentrated in vacuo. The resulting crude material was purified using Biotage® flash 4OS (2:1 hexanes / ethyl acetate) to afford 250 mg (24%) of the desired product. ¹H NMR (300 MHz, CDCI₃) δ 4.07-4.14 (m, 3 H), 3.58-3.69 (m, 2 H), 2.72-2.90 (m, 3 H), 1.95 (br s, 2 H), 1.36 (s, 9 H), 1.16-1.24 (m, 3 H), 1.06 (d, 3 H); ES-MS m/z 300.2 [M+H⁺]; HPLC RT (min) 2.97.

[066] Step 2: Preparation of tert-butyl 2-cvclopropyl-4-hvdroxy-9-methyl-5,6,8,9- tetrahvdro-7/-/-pyrimido[4,5-d]azepine-7-carboxylate

[067] Sodium ethoxide solution (21 weight % ethanol, 2.24 mL, 1.45 mmol) was added dropwise to a solution of 1- tert-butyl 4-ethyl 6-methyl-5-oxoazepane-1,4-dicarboxylate (290 mg, 0.97 mmol) in ethanol (6 mL). Cyclopropylcarbamidine hydrochloride (175 mg, 1.45 mmol) was added, and the mixture was heated at reflux for 3 h. The contents of the flask were cooled to rt, and the solvent was removed under reduced pressure. The residue was suspended in water and extracted with chloroform (2x). The organic layers were combined and concentrated to afford 200 mg (64%) of crude product, which was used in the next step without further purification. ¹H NMR (300 MHz, CDCI₃) δ 4.01-4.06 (m, 1 H), 3.37-3.67 (m, 4 H), 2.74-3.00 (m, 4 H), 1.84 (br s, 1 H), 1.44 (s, 9 H), 1.18 (d, 1 H), 0.78-0.92 (m, 4 H); ES-MS m/z 320.2 [M+H⁺]; HPLC RT (min) 2.50.

[068] Step 3: Preparation of 4-chloro-2-cvclopropyl-9-methyl-6,7.8,9-tetrahydro-5H- pyrimido[4,5-d]azepine

[069] tert-Butyl 2-cyclopropyl-4-hydroxy-9-methyl-5,6,8,9-tetrahydro-7H-pyrimido[4,5- d]azepine-7-carboxylate (200 mg, 0.63 mmol) was suspended in phosphorus oxychloride (0.6 ml_, 6.3 mmol) and heated to 80°C. Once at 80°C, N,N-dimethylaniline (0.04 mL, 0.31 mmol) was added, and the reaction mixture was heated for an additional hour. The mixture was then cooled to rt, poured into ice, and stirred for 1 h. The aqueous solution was brought to pH 8-9 by addition of 2N aqueous sodium hydroxide solution. The basic aqueous solution was extracted with chloroform (2x), dried over anhydrous sodium sulfate, and concentrated in vacuo to afford 80 mg of desired product (54%). ¹H NMR (300 MHz, CD₃OD) δ 3.28-3.36 (m, 2 H), 3.11-3.30 (m, 2 H), 2.76-2.82 (m, 2 H), 2.15- 2.20 (m, 1 H), 1.45 (br s, 1 H), 1.34 (d, 3 H), 0.94-1.10 (m, 4 H); ES-MS m/z 238.4 [M+H⁺]; HPLC RT (min) 1.40.

[070] Step 4: Preparation of tert-butyl 4-chloro-2-cvclopropyl-9-methyl-5,6,8,9- tetrahvdro-7H-pyrimido[4,5-d]azepine-7-carboxylate

[071] To a solution of 4-chloro-2-cyclopropyl-9-methyl-6,7,8,9-tetrahydro-5H- pyrimido[4,5-d]azepine (60 mg, 0.25 mmol) in THF (2 mL) was added water (0.5 mL), sodium bicarbonate (23 mg, 0.28 mmol), and di- tert-butyl dicarbonate (61 mg, 0.28 mmol). The mixture was stirred at rt for 16 h, then was diluted with water, and extracted with ethyl acetate. The organic layer was separated, dried over anhydrous sodium sulfate, and concentrated in vacuo. The resulting crude material was purified using Biotage® flash 4OS (3:1 hexanes / ethyl acetate) to afford 38 mg (45%) of the desired product. ¹H NMR (300 MHz, CD₃OD) δ 3.50-3.70 (m, 2 H), 3.41-3.49 (m, 1 H), 3.32-3.40 (m, 2 H), 3.14-3.42 (m, 2 H), 2.18-2.32 (m, 1 H), 1.52 (s, 9 H), 1.32 (d, 3 H), 0.93-1.08 (m, 4 H); ES-MS m/z 338.1 [M+H⁺]; HPLC RT (min) 3.75.

[072] Step 5: Preparation of 2-cvclopropyl-9-methyl-4-(3.3,3-trifluoropropoxy)-6,7,8,9- tetrahvdro-5H-pyrimido[4,5-d]azepine dihvdrochloride

[073] To a solution of 3,3,3-trifluoropropan-1-ol (14 mg, 0.12 mmol) in 1 ,4-dioxane (1 ml.) was added potassium tert-butoxide (58 mg, 0.52 mmol), and the resulting mixture was stirred at rt for 15 min. tert-Butyl 4-chloro-2-cyclopropyl-9-methyl-5,6,8,9-tetrahydro- 7H-pyrimido[4,5-d]azepine-7-carboxylate (35 mg, 0.10 mmol) was then added, and the mixture was heated at 80°C overnight. The reaction was cooled to rt and filtered through a pad of Celite®. The filtrate was concentrated under reduced pressure, and the crude material was re-dissolved in 1 ,4-dioxane. A 4M solution of hydrochloric acid in dioxane (0.1 ml_, 0.4 mmol) was added, and the mixture was stirred for 3 h. The dioxane solvent was removed under reduced pressure, and the crude residue was triturated with ethyl acetate to afford 12 mg (29%) of desired product. ¹H NMR (300 MHz, CD₃OD) δ 4.75 (t, 2 H), 3.61-3.71 (m, 1 H), 3.41-3.62 (m, 4 H), 3.12-3.34 (m, 2 H), 2.77-2.83 (m, 2 H), 2.36- 2.42 (m, 1 H), 1.57 (d, 3 H), 1.38-1.50 (m, 5 H); ES-MS m/z 316.2 [M+H⁺]; HPLC RT (min) 1.90.

[074] Example 5

Preparation of 2-cvclopropyl-7-methyl-4-(3,3,3-trifluoropropoxy)-6,7,8,9-tetrahvdro-

5H-pyrimido[4,5-d]azepine

[075] 2-Cyclopropyl-4-(3,3,3-trifluoropropoxy)-6,7,8,9-tetrahydro-5H-pyrimido[4,5- d]azepine dihydrochloride of Example 2 (92 mg, 0.3 mmol) was suspended in ethyl acetate and washed with saturated aqueous sodium bicarbonate solution. The organic layer was separated, dried (MgSO₄), and concentrated under reduced pressure to a colorless oil. The oil was dissolved in anhydrous DMF (0.5 mL) and added to a suspension of 95% sodium hydride (8 mg, 0.3 mmol) in DMF (0.5 mL). The mixture was stirred for 15 min at ambient temperature, lodomethane (20 μL , 0.3 mmol) was added, and the solution was stirred for an additional 4 h. The contents of the flask were partitioned between ethyl acetate and water. The organic layer was separated and concentrated to a crude oil under reduced pressure. The resulting crude was purified by HPLC eluted with an acetonitrile / water mixture to provide the title compound as a yellow solid (20 mg, 27%). ¹H NMR (300 MHz, CD₃OD) δ 4.55 (t, 2 H), 3.02-2.99 (m, 2 H), 2.90- 2.86 (m, 2 H), 2.73-2.65 (m, 2 H), 2.64-2.60 (m, 2 H), 2.55-2.51 (m, 2 H), 2.37 (s, 3 H), 2.10-2.01 (m, 1 H), 1.06-0.97 (m, 4 H); ES-MS m/z316.2 [M+H⁺]; HPLC RT (min) 1.71.

[076] Example 6

Preparation of 7-acetyl-2-cvclopropyl-4-(3,3,3-trifluoropropoxy) -6,7,8,9-tetrahydro-

5H-pyrimido[4,5-d]azepine

[077] 2-Cyclopropyl-4-(3,3,3-trifluoropropoxy)-6,7,8,9-tetrahydro-5H-pyrimido[4,5- d]azepine dihydrochloride of Example 2 (92 mg, 0.3 mmol) was suspended in ethyl acetate and washed with saturated aqueous sodium bicarbonate solution. The organic layer was separated, dried (MgSO₄), and concentrated under reduced pressure to a colorless oil. The oil was dissolved in anhydrous dichloromethane (1 mL) and triethylamine (0.13 mL, 0.9 mmol) and treated with acetyl chloride (30 μL, 0.45 mmol). The solution was stirred at ambient temperature for 4 h. The contents of the flask were partitioned between ethyl acetate and water. The organic layer was separated and concentrated to a crude oil under reduced pressure. The resulting crude was purified by HPLC eluted with an acetonitrile / water mixture to provide the title compound as a yellow solid (82 mg, 99%). ¹H NMR (300 MHz, CD₃OD) δ 4.59-4.53 (m, 2 H), 3.76-3.64 (m, 4 H), 3.13-3.09 (m, 1 H), 3.04-3.00 (m, 1 H), 2.98-2.94 (m, 1 H), 2.89-2.85 (m, 1 H), 2.75- 2.60 (m, 2 H), 2.15 (d, 3 H), 2.10-2.02 (m, 1 H), 1.07-0.97 (m, 4 H); ES-MS m/z 344.3 [M+H⁺]; HPLC RT (min) 2.07. [078] Using the methods described for Examples 1 through 6, and using the appropriate starting materials, the compounds of Table 1 were prepared in analogous manner.

Table 1

Table 1

Table 1

Table 1

Table 1

Table 1

Table 1

Methods of Use

[079] As used herein, various terms are defined below.

[080] When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[081] The term "subject" as used herein includes mammals (e.g., humans and animals).

[082] The term "treatment" includes any process, action, application, therapy, or the like, wherein a subject, including a human being, is provided medical aid with the object of improving the subject's condition, directly or indirectly, or slowing the progression of a condition or disorder in the subject.

[083] The term "combination therapy" or "co-therapy" means the administration of two or more therapeutic agents to treat a disease, condition, and/or disorder. Such administration encompasses co-administration of two or more therapeutic agents in a substantially simultaneous manner, such as in a single capsule having a fixed ratio of active ingredients or in multiple, separate capsules for each inhibitor agent. In additioi such administration encompasses use of each type of therapeutic agent in a sequential manner.

[084] The phrase "therapeutically effective" means the amount of each agent administered that will achieve the goal of improvement in a disease, condition, and/or disorder severity, while avoiding or minimizing adverse side effects associated with the given therapeutic treatment.

[085] The term "pharmaceutically acceptable" means that the subject item is appropriate for use in a pharmaceutical product.

[086] The compounds of Formula (I) of this invention are expected to be valuable as therapeutic agents. Accordingly, an embodiment of this invention includes a method of treating the various conditions in a patient (including mammals) which comprises administering to said patient a composition containing an amount of the compound of Formula (I) that is effective in treating the target condition.

[087] The compounds of the present invention interact with the 5-HT_2C receptor and may be used in the treatment or prevention of diseases and/or behaviors that involve the 5-HT_2C receptor. These diseases and/or behaviors include, for example, obesity, obesity related disorders such as diabetes, feeding behavior, eating disorders such as bulimia, anorexia nervosa and premenstrual tension.

[088] For example, an object of this invention is to provide methods for treating obesity and inducing weight loss in an individual by administration of a compound of the invention. The method of the invention comprises administering to an individual a therapeutically effective amount of at least one compound of the invention, or a prodrug thereof, which is sufficient to induce weight loss. The invention further comprises a method of preventing weight gain in an individual by administering an amount of at least one compound of the invention, or a prodrug thereof, which is sufficient to prevent weight gain.

[089] Further diseases and/or behaviors which can be treated or prevented include central nervous disorders, depressions, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction and chronic fatigue syndrome.

[090] The present invention also relates to the use of the compounds of this invention for the treatment of obesity-related diseases including associated dyslipidemia and other obesity- and overweight-related complications such as, for example, cholesterol gallstones, gallbladder disease, gout, cancer (e.g., colon, rectum, prostate, breast, ovary, endometrium, cervix, gallbladder, and bile duct), menstrual abnormalities, infertility, polycystic ovaries, osteoarthritis, and sleep apnea, as well as for a number of other pharmaceutical uses associated therewith, such as the regulation of appetite and food intake, dyslipidemia, hypertriglyceridemia, Syndrome X, type 2 diabetes (non-insulin- dependent diabetes), atherosclerotic diseases such as heart failure, hyperlipidemia, hypercholesteremia, low HDL levels, hypertension, cardiovascular disease (including atherosclerosis, coronary heart disease, coronary artery disease, and hypertension), cerebrovascular disease such as stroke, and peripheral vessel disease. The compounds of this invention may also be useful for treating physiological disorders related to, for example, regulation of insulin sensitivity, inflammatory response, plasma triglycerides, HDL, LDL and cholesterol levels and the like.

[091] Compounds of Formula (I) may be administered alone or in combination with one or more additional therapeutic agents. Combination therapy includes administration of a single pharmaceutical dosage formulation which contains a compound of Formula (I) and one or more additional therapeutic agents, as well as administration of the compound of Formula (I) and each additional therapeutic agents in its own separate pharmaceutical dosage formulation. For example, a compound of Formula (I) and a therapeutic agent may be administered to the patient together in a single oral dosage composition such as a tablet or capsule, or each agent may be administered in separate oral dosage formulations.

[092] Where separate dosage formulations are used, the compound of Formula (I) and one or more additional therapeutic agents may be administered at essentially the same time (e.g., concurrently) or at separately staggered times (e.g., sequentially).

[093] For example, the compound of Formula (I) may be used in combination with other therapies and drugs useful for the treatment of obesity. For example, anti-obesity drugs include β-3 adrenergic receptor agonists such as CL 316,243; cannabinoid (e.g., CB-1) antagonists such as Rimonabant; neuropeptide-Y receptor antagonists; neuropeptide Y5 inhibitors; apo-B/MTP inhibitors; 11 β-hydroxy steroid dehydrogenase-1 inhibitors; peptide YY₃-₃₆ or analogs thereof; MCR4 agonists; CCK-A agonists; monoamine reuptake inhibitors; sympathomimetic agents; dopamine agonists; melanocyte-stimulating hormone receptor analogs; melanin concentrating hormone antagonists; leptin; leptin analogs; leptin receptor agonists; galanin antagonists; lipase inhibitors; bombesin agonists; thyromimetic agents; dehydroepiandrosterone or analogs thereof; glucocorticoid receptor antagonists; orexin receptor antagonists; ciliary neurotrophic factor; ghrelin receptor antagonists; histamine-3 receptor antagonists; neuromedin U receptor agonists; appetite suppressants, such as, for example, sibutramine (Meridia); and lipase inhibitors, such as, for example, orlistat (Xenical). The compounds of the present invention may also be administered in combination with a drug compound that modulates digestion and/or metabolism such as drugs that modulate thermogenesis, lipolysis, gut motility, fat absorption, and satiety.

[094] In addition, the compound of Formula (I) may be administered in combination with one or more of the following agents for the treatment of diabetes or diabetes-related disorders including PPAR ligands (agonists, antagonists), insulin secretagogues, for example, sulfonylurea drugs and non-sulfonylurea secretagogues, α-glucosidase inhibitors, insulin sensitizers, hepatic glucose output lowering compounds, and insulin and insulin derivatives. Such therapies may be administered prior to, concurrently with, or following administration of the compounds of the invention. Insulin and insulin derivatives include both long and short acting forms and formulations of insulin. PPAR ligands may include agonists and/or antagonists of any of the PPAR receptors or combinations thereof. For example, PPAR ligands may include ligands of PPAR-α, PPAR-γ, PPAR-δ or any combination of two or three of the receptors of PPAR. PPAR ligands include, for example, rosiglitazone, troglitazone, and pioglitazone. Sulfonylurea drugs include, for example, glyburide, glimepiride, chlorpropamide, tolbutamide, and glipizide, α- glucosidase inhibitors that may be useful in treating diabetes when administered with a compound of the invention include acarbose, miglitol, and voglibose. Insulin sensitizers that may be useful in treating diabetes include PPAR-γ agonists such as the glitazones (e.g., troglitazone, pioglitazone, englitazone, MCC-555, rosiglitazone, and the like) and other thiazolidinedione and non-thiazolidinedione compounds; biguanides such as metformin and phenformin; protein tyrosine phosphatase- 1 B (PTP-1B) inhibitors; dipeptidyl peptidase IV (DPP-IV) inhibitors, and 11 beta-HSD inhibitors. Hepatic glucose output lowering compounds that may be useful in treating diabetes when administered with a compound of the invention include glucagon anatgonists and metformin, such as Glucophage and Glucophage XR. Insulin secretagogues that may be useful in treating diabetes when administered with a compound of the invention include sulfonylurea and non-sulfonylurea drugs: GLP-1 , GIP, PACAP, secretin, and derivatives thereof; nateglinide, meglitinide, repaglinide, glibenclamide, glimepiride, chlorpropamide, glipizide. GLP-1 includes derivatives of GLP-1 with longer half-lives than native GLP-1 , such as, for example, fatty-acid derivatized GLP-1 and exendin.

[095] Compounds of the invention may also be used in methods of the invention in combination with drugs commonly used to treat lipid disorders in patients. Such drugs include, but are not limited to, HMG-CoA reductase inhibitors, nicotinic acid, fatty acid lowering compounds (e.g., acipimox); lipid lowering drugs (e.g., stanol esters, sterol glycosides such as tiqueside, and azetidinones such as ezetimibe), ACAT inhibitors (such as avasimibe), bile acid sequestrants, bile acid reuptake inhibitors, microsomal triglyceride transport inhibitors, and fibric acid derivatives. HMG-CoA reductase inhibitors include, for example, lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, rivastatin, itavastatin, cerivastatin, and ZD-4522. Fibric acid derivatives include, for example, clofibrate, fenofibrate. bezafibrate, ciprofibrate, beclofibrate, etofibrate, and gemfibrozil. Sequestrants include, for example, cholestyramine, colestipol, and dialkylaminoalkyl derivatives of a cross-linked dextran.

[096] Compounds of the invention may also be used in combination with anti¬ hypertensive drugs, such as, for example, β-blockers and ACE inhibitors. Examples of additional anti-hypertensive agents for use in combination with the compounds of the present invention include calcium channel blockers (L-type and T-type; e.g., diltiazem, verapamil, nifedipine, amlodipine and mybefradil), diuretics (e.g., chlorothiazide, hydrochlorothiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methylchlorothiazide, trichloromethiazide, polythiazide, benzthiazide, ethacrynic acid tricrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamtrenene, amiloride, spironolactone), renin inhibitors, ACE inhibitors (e.g., captopril, zofenopril, fosinopril, enalapril, ceranopril, cilazopril, delapril, pentopril, quinapril, ramipril, lisinopril), AT-1 receptor antagonists (e.g., losartan, irbesartan, valsartan), ET receptor antagonists (e.g., sitaxsentan, atrsentan, neutral endopeptidase (NEP) inhibitors, vasopepsidase inhibitors (dual NEP-ACE inhibitors) (e.g., omapatrilat and gemopatrilat), and nitrates.

[097] The compound of Formula (I) may also be utilized, in free base form or in compositions, as well as in research and diagnostics or as analytical reference standards, and the like, which are well known in the art. Therefore, the present invention includes compositions which are comprised of an inert carrier and an effective amount of a compound of Formula (I), or a salt, or ester thereof. An inert carrier is any material which does not interact with the compound to be carried and which lends support, means of conveyance, bulk, traceable material, and the like to the compound to be carried. An effective amount of the compound is that amount which produces a result or exerts an influence on the particular procedure being performed.

[098] It is anticipated that prodrug forms of the compounds of this invention will prove useful in certain circumstances, and such compounds are also intended to fall within the scope of the invention. Prodrug forms may have advantages over the parent compounds exemplified herein, in that they are better absorbed, better distributed, more readily penetrate the central nervous system, are more slowly metabolized or cleared, etc. Prodrug forms may also have formulation advantages in terms of crystallinity or water solubility. For example, compounds of the invention having one or more hydroxyl groups may be converted to esters or carbonates bearing one or more carboxyl, hydroxyl or amino groups, which are hydrolyzed at physiological pH values or are cleaved by endogenous esterases or lipases in vivo (see, e.g., U.S. Patent Nos. 4,942,184; 4,960,790; 5,817,840; and 5,824,701 , all of which are incorporated herein by reference in their entirety, and references therein).

Pharmaceutical Compositions

[099] Based on the above tests, or other well known assays used to determine the efficacy for treatment of conditions identified above in mammals, and by comparison of these results with the results of known medicaments that are used to treat these conditions, the effective dosage of the compounds of this invention can readily be determined for treatment of each desired indication. The amount of the active ingredient to be administered in the treatment of one of these conditions can vary widely according to such considerations as the particular compound and dosage unit employed, the mode of administration, the period of treatment, the age and sex of the patient treated, and the nature and extent of the condition treated.

[100] The total amount of the active ingredient to be administered may generally range from about 0.001 mg/kg to about 200 mg/kg. A unit dosage may contain from about 0.05 mg to about 1500 mg of active ingredient, and may be administered one or more times per day. The daily dosage for administration by injection, including intravenous, intramuscular, subcutaneous, and parenteral injections, and use of infusion techniques may be from about 0.01 to about 200 mg/kg. The daily rectal dosage regimen may be from 0.01 to 200 mg/kg of total body weight. The transdermal concentration may be that required to maintain a daily dose of from 0.01 to 200 mg/kg.

[101] Of course, the specific initial and continuing dosage regimen for each patient will vary according to the nature and severity of the condition as determined by the attending diagnostician, the activity of the specific compound employed, the age of the patient, the diet of the patient, time of administration, route of administration, rate of excretion of the drug, drug combinations, and the like. The desired mode of treatment and number of doses of a compound of the present invention or a pharmaceutically acceptable salt thereof may be ascertained by those skilled in the art using conventional treatment tests.

[102] The compounds of this invention may be utilized to achieve the desired pharmacological effect by administration to a subject in need thereof in an appropriately formulated pharmaceutical composition. A subject, for example, may be a mammal, including a human, in need of treatment for a particular condition or disease. Therefore, the present invention includes pharmaceutical compositions which are comprised of a pharmaceutically acceptable carrier and a pharmaceutically effective amount of a compound identified by the methods described herein, or a pharmaceutically acceptable salt or ester thereof. A pharmaceutically acceptable carrier is any carrier which is relatively non-toxic and innocuous to a patient at concentrations consistent with effective activity of the active ingredient so that any side effects ascribable to the carrier do not vitiate the beneficial effects of the active ingredient. A pharmaceutically effective amount of a compound is that amount which produces a result or exerts an influence on the particular condition being treated. The compounds identified by the methods described herein may be administered with a pharmaceutically-acceptable carrier using any effective conventional dosage unit forms, including, for example, immediate and timed release preparations, orally, parenterally, topically, or the like. [103] For oral administration, the compounds may be formulated into solid or liquid preparations such as, for example, capsules, pills, tablets, troches, lozenges, melts, powders, solutions, suspensions, or emulsions, and may be prepared according to methods known to the art for the manufacture of pharmaceutical compositions. The solid unit dosage forms may be a capsule which can be of the ordinary hard- or soft-shelled gelatin type containing, for example, surfactants, lubricants, and inert fillers such as lactose, sucrose, calcium phosphate, and corn starch.

[104] In another embodiment, the compounds of this invention may be tableted with conventional tablet bases such as lactose, sucrose, and cornstarch in combination with binders such as acacia, cornstarch, or gelatin; disintegrating agents intended to assist the break-up and dissolution of the tablet following administration such as potato starch, alginic acid, corn starch, and guar gum; lubricants intended to improve the flow of tablet granulation and to prevent the adhesion of tablet material to the surfaces of the tablet dies and punches, for example, talc, stearic acid, or magnesium, calcium or zinc stearate; dyes; coloring agents; and flavoring agents intended to enhance the aesthetic qualities of the tablets and make them more acceptable to the patient. Suitable excipients for use in oral liquid dosage forms include diluents such as water and alcohols, for example, ethanol, benzyl alcohol, and polyethylene alcohols, either with or without the addition of a pharmaceutically acceptable surfactant, suspending agent, or emulsifying agent. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. For instance tablets, pills or capsules may be coated with shellac, sugar or both.

[105] Dispersible powders and granules are suitable for the preparation of an aqueous suspension. They provide the active ingredient in admixture with a dispersing or wetting agent, a suspending agent, and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example, those sweetening, flavoring and coloring agents described above, may also be present.

[106] The pharmaceutical compositions of this invention may also be in the form of oil- in-water emulsions. The oily phase may be a vegetable oil such as liquid paraffin or a mixture of vegetable oils. Suitable emulsifying agents may be naturally occurring gums, naturally occurring phosphatides, esters or partial esters derived from fatty acids and hexitol anhydrides, and condensation products of said partial esters. The emulsions may also contain sweetening and flavoring agents. [107] Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil such or in a mineral oil. The oily suspensions may contain a thickening agent. The suspensions may also contain one or more preservatives, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents.

[108] Syrups and elixirs may be formulated with sweetening agents such as, for example, glycerol, propylene glycol, sorbitol, or sucrose. Such formulations may also contain a demulcent, and preservative, flavoring and coloring agents.

[109] The compounds of this invention may also be administered parenterally, that is, subcutaneously, intravenously, intramuscularly, or interperitoneally, as injectable dosages of the compound in a physiologically acceptable diluent with a pharmaceutical carrier, with or without the addition of a pharmaceutically acceptable surfactants, suspending agents, emulsifying agents or other pharmaceutical adjuvants.

[110] The parenteral compositions of this invention may typically contain from about 0.5% to about 25% by weight of the active ingredient in solution. Preservatives and buffers may also be used advantageously. In order to minimize or eliminate irritation at the site of injection, such compositions may contain a non-ionic surfactant having a hydrophile-lipophile balance (HLB) of from about 12 to about 17. The quantity of surfactant in such formulation ranges from about 5% to about 15% by weight. The surfactant can be a single component having the above HLB or can be a mixture of two or more components having the desired HLB.

[111] The pharmaceutical compositions may be in the form of sterile injectable aqueous suspensions. Such suspensions may be formulated according to known methods using suitable dispersing or wetting agents and suspending agents.

[112] The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent. Diluents and solvents that may be employed are, for example, water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile fixed oils are conventionally employed as solvents or suspending media. For this purpose, any bland, fixed oil may be employed including synthetic mono or diglycerides. In addition, fatty acids such as oleic acid may be used in the preparation of injectables.

[113] A composition of the invention may also be administered in the form of suppositories for rectal administration of the drug. These compositions may be prepared by mixing the drug with a suitable non-irritation excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such material are, for example, cocoa butter and polyethylene glycol.

[114] Another formulation employed in the methods of the present invention employs transdermal delivery devices ("patches"). Such transdermal patches may be used to provide continuous or discontinuous infusion of the compounds of the present invention in controlled amounts. The construction and use of transdermal patches for the delivery of pharmaceutical agents is well known in the art (see, e.g., U.S. Patent No. 5,023,252, incorporated herein by reference). Such patches may be constructed for continuous, pulsatile, or on demand delivery of pharmaceutical agents.

[115] It may be desirable or necessary to introduce the pharmaceutical composition to the patient via a mechanical delivery device. The construction and use of mechanical delivery devices for the delivery of pharmaceutical agents is well known in the art. For example, direct techniques for administering a drug directly to the brain usually involve placement of a drug delivery catheter into the patient's ventricular system to bypass the blood-brain barrier. One such implantable delivery system, used for the transport of agents to specific anatomical regions of the body, is described in U.S. Patent No. 5,011 ,472, incorporated herein by reference.

[116] The compositions of the invention may also contain other conventional pharmaceutically acceptable compounding ingredients, generally referred to as carriers or diluents, as necessary or desired. Any of the compositions of this invention may be preserved by the addition of an antioxidant such as ascorbic acid or by other suitable preservatives. Conventional procedures for preparing such compositions in appropriate dosage forms can be utilized.

[117] The compounds identified by the methods described herein may be administered as the sole pharmaceutical agent or in combination with one or more other pharmaceutical agents where the combination causes no unacceptable adverse effects. For example, the compounds of this invention can be combined with known anti-obesity, or with known antidiabetic or other indication agents, and the like, as well as with admixtures and combinations thereof.

[118] The compounds identified by the methods described herein may also be utilized, in free base form or in compositions, in research and diagnostics, or as analytical reference standards, and the like. Therefore, the present invention includes compositions which are comprised of an inert carrier and an effective amount of a compound identified by the methods described herein, or a salt or ester thereof. An inert carrier is any material which does not interact with the compound to be carried and which lends support, means of conveyance, bulk, traceable material, and the like to the compound to be carried. An effective amount of compound is that amount which produces a result or exerts an influence on the particular procedure being performed.

[119] Formulations suitable for subcutaneous, intravenous, intramuscular, and the like; suitable pharmaceutical carriers; and techniques for formulation and administration may be prepared by any of the methods well known in the art (see, e.g., Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton, Pa., 20^th edition, 2000)

[120] The structures, materials, compositions, and methods described herein are intended to be representative examples of the invention, and it will be understood that the scope of the invention is not limited by the scope of the examples. Those skilled in the art will recognize that the invention may be practiced with variations on the disclosed structures, materials, compositions and methods, and such variations are regarded as within the ambit of the invention.

Evaluation of Biological Activity

[121] In order that this invention may be better understood, the following examples are set forth. These examples are for the purpose of illustration only, and are not to be construed as limiting the scope of the invention in any manner. All publications mentioned herein are incorporated by reference in their entirety.

[122] Demonstration of the activity of the compounds of the present invention may be accomplished through in vitro, ex vivo, and in vivo assays that are well known in the art. For example, to demonstrate the activity of the compounds of the present invention, the following assays may be used.

In Vitro Assays

[123] Activity of the compounds of Formula (I) may be determined by measurement of their binding affinity and agonist activity at the 5-HT_2C receptor. The following assays were performed to determine the effect of the compounds of Formula (I) on the 5-HT_2C receptor.

[124] Membranes prepared from an AV-12 cell line expressing human recombinant 5- HT_2C receptor were used for the [¹²⁵I]-DOI displacement assay (SPA format) to examine binding affinity of compounds of Formula (I). The 5-HT_2C SPA binding assay was performed in a buffer containing 50 mM Tris (pH7.4), 10 mM MgCI₂, 10 μM pargyline, 0.1% sodium ascorbate, 0.5 mM EDTA, and 0.1% BSA. All assay components were diluted in this buffer. [¹²⁵I] DOI (NEN - Cat. No. NEX255) and wheat agglutinin SPA beads PEI treated- type B (RPNQ0004, Amersham, Piscataway, NJ) were used for this binding assay. In a 96-well flex plate, 200 pM of the radiolabel was added followed by the appropriately dosed compounds and references. Membranes (5 μg/well, 50 μl_) and 50 μl of the SPA beads (250 μg/well) were added to each well. The reaction plates were mixed on a plate shaker for 20-30 minutes. The beads were then allowed to settle for about 1 hour before they were counted in a Wallac Microbeta.

[125] The functional activity of compounds of Formula (I) was measured using a FLIPR calcium mobilization assay in cells transfected with recombinant receptor. AV-12 cells expressing 5-HT_2C receptors were placed into 96-well black plates (5 x10⁴ cells per well/ 100 μL DMEM medium. The DMEM medium contained 10% dialysis FBS, 2 mM L- glutamine, 20 mM Hepes, 1 mg/ml G418, and 1 % antibiotic. The cell plates are incubated overnight at 37°C, 5% of CO₂. Following incubation, the cell culture medium was removed, and 160 μL of 1X loading buffer (1X Hank's buffer contains 20 mM Hepes and 2.5 mM probenecid dissolved in 0.5 N NaOH) was added with calcium dye (Calcium 3 Assay Kit, Molecular Devices, Inc) into the cell plates. The cells were incubated at 37°C, 5% CO₂ for 1 hour. Thereafter, the cell plates and compound dilution plates were placed into the FLIPR instrument, and 40 μL of varying concentrations of test compound or reference compound (alpha-Me-5-HT) were added into the cell plates. Increases in intracellular calcium were recorded at 488 nm during 3 minutes with the FLIPR. Peak fluorescence counts minus basal counts from 1 sec to 180 sec time points were used to determine agonist activity. Iterative curve-fitting and parameter estimations were analyzed using a four-parameter logistic equation and a program that generates dose- response curves. The potency of the compound was expressed in terms of the concentration required to achieve half-maximal stimulation (EC₅₀) while the efficacy of the ligand was expressed as the percentage of its maximal stimulation relative to the maximal stimulation observed with the alpha-Me-5-HT curve from the same plate (E/Emax).

In Vivo Assays

Evaluation of Compound's Efficacy on the Reduction of Food Intake in Lean Overnight Fasted Rats

Fasted-Refed Acute Feeding Assay

[126] The purpose of this protocol is to determine the effect of a single dose of an unknown compound on food consumption of lean overnight fasted rats. The fasted-refed rat model is frequently used in the field of obesity to identify compounds with potential for anorectic effects. This animal model has been successfully used in the identification and characterization of the efficacy profile of compounds that are or have been used in the management of body weight in obese humans (see, e.g., Balvet, et al., Gen. Pharmacol. 13:293-297, 1982; Θrignaschi, et al., Br. J. Pharmacol. 127:1190-1194, 1999; McTavish and Heel, Drug 43:713-733, 1992; Rowland, et al., Life Sci. 36:2295-2300, 1985).

[127] A typical study includes 60-80 male Wistar rats (n=10/treatment group) with an average body weight of approximately 280 g. Rats are kept in standard animal rooms under controlled temperature and humidity and a 12/12 light dark cycle. Rats are single- housed in suspended cages with a mesh floor. Water and food are continuously available unless the animals are being fasted for the study.

[128] The rats are fasted overnight during the dark phase (total of approx. 16-18 hr). The animal is dosed with an assigned treatment (2 mg/mL). One hour after dosing, pre- weighed food jars are returned to the cage. Food intake is recorded 30, 60, 90, 180, and 240 minutes and 24 hours post-food return. At each time point, spillage is returned to the food jar and then the food jars are weighed. The amount of food consumed is determined for each time point. Difference between treatment group is determined using appropriate statistical analysis.

Evaluation of Compound's Efficacy on the Reduction of Body Weight and Food and Water Consumption in Obese Zucker fa/fa Rats

Chronic Feeding Assay

[129] The purpose of this protocol is to determine the effect of chronic administration of an unknown compound on body weight and food and water consumption in obese Zucker (fa/fa) rats. Obese Zucker rats are frequently used in the determination of compound efficacy in the reduction of body weight. This animal model has been successfully used in the identification and characterization of the efficacy profile of compounds that are or have been used in the management of body weight in obese humans (see, e.g., Al- Barazanji, et al., Obes Res. 8:317-323, 2000; Assimacopoulos-Jeannet, et al., Am. J. Physiol. 260(2 Pt 2):R278-283, 1991 ; Dryden, et al., Horm. Metab. Res. 31 :363-366, 1999; Edwards and Stevens, Pharmacol. Biochem. Behav. 47:865-872, 1994; Grinker, et al., Pharmacol. Biochem. Behav. 12:265-275, 1980).

[130] A typical study includes 60-80 male Zucker (fa/fa) rats (approximatelylO/treatment group) with an average body weight of approximately 550 g. Rats are kept in standard animal rooms under controlled temperature and humidity and a 12/12 light/dark cycle. Water and food are continuously available. Rats are single-housed in large rat shoeboxes containing grid floor. Animals are adapted to the grid floors and sham-dosed with study vehicle for at least four days before the recording of two-days baseline measurement of body weight and 24 h food and water consumption. Rats are assigned to one of 6-8 treatment groups based upon their baseline body weight. The groups are set up so that the mean and standard error of the mean of body weight are similar.

[131] Animals are orally gavaged (2 ml_/kg) daily before the dark phase of the light/dark cycle for a pre-determined number of days (typically 6-14 days) with their assigned dose/compound. At this time, body weight, food and water consumption are measured. On the final day, body weight is measured and animals are euthanized by CO₂ inhalation.

[132] Other embodiments of the invention will be apparent to the skilled in the art from a consideration of this specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

Claims

Claims

1) A compound of Formula (I)

(I) wherein R¹ is

. (C₁-C₄)alkyl,

• phenyl optionally substituted with halo, or

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl;

R² is

• C₁-C₆ alkyl,

• halo

• piperidin-1-yl

• pyrrolidin-1-yl

• phenylpyrrolidin-1-yl optionally substituted on the phenyl ring with up to two groups selected from halo, (C₁-C₃)alkyl, (C_rC₃)alkoxy, or CF₃,

• phenylpiperidin-1 -yl optionally substituted on the phenyl ring with up to two groups selected fromhalo or CF₃,

• phenoxypiperidin-1 -yl optionally substituted on the phenyl ring with up to two groups selected from halo or CF₃,

• phenylpiperazin-1 -yl optionally substituted on the phenyl ring with up to two groups selected from (C₁-C₃)alkyl, halo, CF₃, or (C₁-C₃)alkoxy,

• -NR⁵R⁶ wherein R⁵ is H or (C₁-C₃)alkyl, and

R⁶ is (C₁-C₃)alkyl optionally substituted with

• indoly-2-yl optionally substituted with halo,

• phenyl optionally substituted with up to two groups selected from (C₁-C₃)alkoxy, or

• benzodioxan-6-yl, or

• OR⁷ wherein R⁷ is

• H,

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl,

• 2,3-dihydro-inden-2-yl,

• tetrahydrofuran-yl, or

• (C₁-C₆)alkyl optionally substituted with

• F up to the perfluoro level,

• (C₃-C₆)cycloalkyl,

• (CrC₃)alkoxy,

• — N[(C₁-C₃)alkyl]₂,

• — NH[(C₁-C₃)alkyl],

• morpholin-1-yl,

• phenyl optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, NO₂, (C₁-C₃)alkoxy, or N[(C₁-C₃)alkyl]₂,

• 2,3-dihydro-benzo[1 ,4]dioxin-2-yl, • 2,3-dihydro-1 H-indol-2-yl,

• tetrahydrofuran-yl,

• 2-oxo-2, 3-dihydro-benzoimidazol-1 -yl,

• 2-oxo-pyrrolidin-1-yl, or

• — N[(C₁-C₃)alkyl]phenyl, wherein the phenyl is optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, (C₁- C₃)alkoxy, and — N[(C₁-C₃)alkyl]₂;

R³ is H or (C₁-C₃)alkyl; and

R⁴ is H, methyl, -C(O)O-R⁸, or -C(O)R⁹; wherein

R⁸ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)aIkyI, (C₁-C₃)alkoxy, or CF₃, and

R⁹ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃;

or pharmaceutically acceptable salts thereof.

2. The compound of claim 1 , wherein

R¹ is

• (C₁-C₄)alkyl, or

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)aIkyI;

R² is

• C₁-C₆ alkyl,

• halo • phenylpyrrolidin-1-yl optionally substituted on the phenyl ring with up to two groups selected from halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃, . -NR⁵R⁶ wherein

R⁵ is H or (C₁-C₃)alkyl, and

R⁶ is (C₁-C₃)alkyl optionally substituted with

• indoly-2-yl optionally substituted with halo,

• phenyl optionally substituted with up to two groups selected from (C₁-C₃)alkoxy, or

• benzodioxan-6-yl, or

• OR⁷ wherein R⁷ is

• H,

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl,

• 2,3-dihydro-inden-2-yl,

• tetrahydrofuran-yl, or

• (C₁-C₆)alkyl optionally substituted with

• F up to the perfluoro level,

• (C₃-C₆)cycloalkyl,

• (C₁-C₃)alkoxy,

• — N[(C₁-C₃)alkyl]₂,

• — NH[(C₁-C₃)alkyl],

• morpholin-1-yl, • phenyl optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, NO₂, (C₁-C₃)alkoxy, or N[(C₁-C₃)alkyl]₂,

• 2,3-dihydro-benzo[1 ,4]dioxin-2-yl,

• 2,3-dihydro-1 H-indol-2-yl,

• tetrahydrofuran-yl,

• 2-oxo-2,3-dihydro-benzoimidazol-1 -yl,

• 2-oxo-pyrrolidin-1-yl, or

• — N[(C₁-C₃)alkyl]phenyl, wherein the phenyl is optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, (C₁- C₃)alkoxy, and — N[(C₁-C₃)alkyl]₂;

R³ is H or (C₁-C₃)alkyl; and

R⁴ is H, methyl, -C(O)O-R⁸, or -C(O)R⁹; wherein

R⁸ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃, and

R⁹ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃.

3. The compound of claim 1 , wherein

R¹ is

• (C₁-C₄)alkyl, or

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl; R² is

• phenylpyrrolidin-1-yl optionally substituted on the phenyl ring with up to two groups selected from halo, (Ci-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃,

• -NR⁵R⁶ wherein

R⁵ is H or (C₁-C₃)alkyl, and

R⁶ is (C₁-C₃)alkyl optionally substituted with

• indoly-2-yl optionally substituted with halo,

• phenyl optionally substituted with up to two groups selected from (C₁-C₃)alkoxy, or

• benzodioxan-6-yl, or

• OR⁷ wherein R⁷ is

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl, or

• (C₁-C₆)alkyl optionally substituted with

• F up to the perfluoro level,

• (C₃-C₆)cycloalkyl,

• (C₁-C₃)alkoxy,

• phenyl optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, NO₂, (C₁-C₃)alkoxy, or N[(C₁-C₃)alkyl]₂;

R³ is H or (C₁-C₃)alkyl; and R⁴ is H, methyl, -C(O)O-R⁸, or -C(O)R⁹; wherein

R⁸ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃, and

R⁹ is (C₁-C₄)alkyl or phenyl optionally substituted with halo, (C₁-C₃)alkyl, (C₁-C₃)alkoxy, or CF₃.

4. The compound of claim 1 , wherein

R¹ is (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl;

R² is

• phenylpyrrolidin-1-yl optionally substituted on the phenyl ring with up to two groups selected from halo, (C₁-C₃)alkyl, (C₁-C₃)aIkoxy, or CF₃, or

• OR⁷ wherein R⁷ is

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl, or

• (C₁-C₆)alkyl optionally substituted with

• F up to the perfluoro level,

• (C₃-C₆)cycloalkyl,

• (C₁-C₃)alkoxy,

• — N[(C₁-C₃)alkyl]₂,

• — NH[(C₁-C₃)alkyl],

• morpholin-1-yl,

• phenyl optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, NO₂, (C₁-C₃)alkoxy, or N[(C₁-C₃)alkyl]_2l

• 2,3-dihydro-benzo[1 ,4]dioxin-2-yl,

• 2,3-dihydro-1 H-indol-2-yl,

• tetrahydrofuran-yl,

• 2-0X0-2, 3-dihydro-benzoimidazol-1 -yl,

• 2-oxo-pyrrolidin-1-yl, or

• — N[(C₁-C₃)alkyl]phenyl, wherein the phenyl is optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, (C₁- C₃)alkoxy, and — N[(C₁-C₃)alkyl]₂;

R³ is H or (C₁-C₃)alkyl; and

R⁴ is H, methyl.

5. The compound of claim 1 , wherein

R¹ is (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl;

R² is

• OR⁷ wherein R⁷ is

• (C₃-C₆)cycloalkyl optionally substituted with (C₁-C₃)alkyl, or

• (C₁-C₆)alkyl optionally substituted with

• F up to the perfluoro level,

• (C₃-C₆)cycloalkyl,

• (C₁-C₃)alkoxy, or

• phenyl optionally substituted with up to two groups selected from CF₃, halo, (C₁-C₃)alkyl, NO₂, (C₁-C₃)all<oxy, or N[(C_rC₃)alkyl]₂;

R³ is H; and

R⁴ is H or methyl.

6. A pharmaceutical composition comprising a therapeutically effective amount of a compound of claim 1 , or a pharmaceutically acceptable salt or ester, in combination with a pharmaceutically acceptable carrier.

7. A pharmaceutical composition comprising a therapeutically effective amount of a compound of claim 1 , or a pharmaceutically acceptable salt thereof, in combination with a pharmaceutically acceptable carrier and one or more pharmaceutical agents.

8. The pharmaceutical composition of claim 7, wherein said pharmaceutical agent is selected from the group consisting of PPAR ligands, insulin secretagogues, sulfonylurea drugs, α-glucosidase inhibitors, insulin sensitizers, hepatic glucose output lowering compounds, insulin and insulin derivatives, biguanides, protein tyrosine phosphatase-1 B, dipeptidyl peptidase IV, 11 beta-HSD inhibitors, anti- obesity drugs, HMG-CoA reductase inhibitors, nicotinic acid, lipid lowering drugs, ACAT inhibitors, bile acid sequestrants, bile acid reuptake inhibitors, microsomal triglyceride transport inhibitors, fibric acid derivatives, β-blockers, ACE inhibitors, calcium channel blockers, diuretics, renin inhibitors, AT-1 receptor antagonists, ET receptor antagonists, neutral endopeptidase inhibitors, vasopepsidase inhibitors, and nitrates.

9. The pharmaceutical composition of claim 7, wherein said pharmaceutical agent is selected from β-3 adrenergic receptor agonists, cannabinoid antagonists, neuropeptide-Y receptor antagonists, neuropeptide Y5 inhibitors, apo-B/MTP inhibitors, 11 β-hydroxy steroid dehydrogenase-1 inhibitors, peptide YY₃.₃₆ or analogs thereof, MCR4 agonists, CCK-A agonists, monoamine reuptake inhibitors, sympathomimetic agents, dopamine agonists, melanocyte-stimulating hormone receptor analogs, melanin concentrating hormone antagonists, leptin, leptin analogs, leptin receptor agonists, gaianin antagonists, lipase inhibitors, bombesin agonists, thyromimetic agents, dehydroepiandrosterone or analogs thereof, glucocorticoid receptor antagonists, orexin receptor antagonists, ciliary neurotrophic factor, ghrelin receptor antagonists, histamine-3 receptor antagonists, neuromedin U receptor agonists, appetite suppressants, and compound that modulates digestion and/or metabolism.

10. A method of regulating food intake comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 or a composition of claim 6.

11. A method of treating obesity, obesity-related disorders, or eating disorders comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 or a composition of claim 6.

12. A method of treating central nervous disorders, depressions, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction and chronic fatigue syndrome comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 or a composition of claim 6.

13. A method of treating diabetes or diabetes-related disorders comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 or a pharmaceutical composition of claim 6.

14. The method of claim 13, wherein said diabetes is selected from the group consisting of type 1 diabetes, type 2 diabetes, maturity-onset diabetes of the young, latent autoimmune diabetes adult, and gestational diabetes.

15. The method of claim 13, wherein said diabetes-related disorder is selected from the group consisting of hyperglycemia, hyperinsulinemia, impaired glucose tolerance, impaired fasting glucose, dyslipidemia, hypertriglyceridemia, and insulin resistance.

16. A method of regulating food intake comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 in combination with one or more pharmaceutical agents.

17. A method of treating obesity, obesity-related disorders, or eating disorders comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 in combination with one or more pharmaceutical agents.

18. The method of claim 16 or 17, wherein said pharmaceutical agent is selected from β-3 adrenergic receptor agonists, cannabinoid antagonists, neuropeptide-Y receptor antagonists, neuropeptide Y5 inhibitors, apo-B/MTP inhibitors, 11 β-hydroxy steroid dehydrogenase-1 inhibitors, peptide YY_3-36 or analogs thereof, MCR4 agonists, CCK-A agonists, monoamine reuptake inhibitors, sympathomimetic agents, dopamine agonists, melanocyte-stimulating hormone receptor analogs, melanin concentrating hormone antagonists, leptin, leptin analogs, leptin receptor agonists, galanin antagonists, lipase inhibitors, bombesin agonists, thyromimetic agents, dehydroepiandrosterone or analogs thereof, glucocorticoid receptor antagonists, orexin receptor antagonists, ciliary neurotrophic factor, ghrelin receptor antagonists, histamine-3 receptor antagonists, neuromedin U receptor agonists, appetite suppressants, and compound that modulates digestion and/or metabolism.

19. A method of treating central nervous disorders, depressions, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction and chronic fatigue syndrome comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 in combination with one or more pharmaceutical agents.

20. A method of treating diabetes or diabetes-related disorders comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 in combination with one or more pharmaceutical agents.

21. The method of claim 20, wherein said pharmaceutical agent is selected from the group consisting of PPAR agonists, sulfonylurea drugs, non-sulfonylurea secretagogues, α-glucosidase inhibitors, insulin sensitizers, insulin secretagogues, hepatic glucose output lowering compounds, insulin, and anti-obesity agents.

22. The method of claim 20, wherein said diabetes is selected from the group consisting of type 1 diabetes, type 2 diabetes, maturity-onset diabetes of the young, latent autoimmune diabetes adult, and gestational diabetes.

23. The method of claim 20, wherein said diabetes-related disorder is selected from the group consisting of hyperglycemia, hyperinsulinemia, impaired glucose tolerance, impaired fasting glucose, dyslipidemia, hypertriglyceridemia, and insulin resistance.

24. A method of treating obesity, obesity-related disorders, eating disorders, diabetes, or diabetes-related disorders comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 in combination with one or more agents selected from the group consisting of HMG-CoA reductase inhibitors, nicotinic acid, lipid lowering drugs, ACAT inhibitors, bile acid sequestrants, bile acid reuptake inhibitors, microsomal triglyceride transport inhibitors, fibric acid derivatives, β-blockers, ACE inhibitors, calcium channel blockers, diuretics, renin inhibitors, AT-1 receptor antagonists, ET receptor antagonists, neutral endopeptidase inhibitors, vasopepsidase inhibitors, and nitrates.

25. The method of claim 24, wherein said diabetes-related disorder is selected from the group consisting of hyperglycemia, hyperinsulinemia, impaired glucose tolerance, impaired fasting glucose, dyslipidemia, hypertriglyceridemia, and insulin resistance.

26. The method of any one of claims 16 to 25, wherein the compound of claim 1 and one or more pharmaceutical agents are administered as a single pharmaceutical dosage formulation.

27. Compounds according to claim 1 for the treatment and/or prophylaxis of obesity, obesity-related disorders, eating disorders, diabetes, diabetes-related disorders, central nervous disorders, depressions, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction and chronic fatigue syndrome.

28. Medicament containing at least one compound according to claim 1 in combination with at least one pharmaceutically acceptable, pharmaceutically safe carrier or excipient.

29. Use of compounds according to claim 1 for manufacturing a medicament for the treatment and/or prophylaxis of obesity, obesity-related disorders, eating disorders, diabetes, diabetes-related disorders, central nervous disorders, depressions, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction and chronic fatigue syndrome.

30. Medicaments according to claim 28 for the treatment and/or prophylaxis of obesity, obesity-related disorders, eating disorders, diabetes, diabetes-related disorders, central nervous disorders, depressions, anxiety disorders, obsessive-compulsive disorders, sleep disorders, sexual dysfunction, psychoses, migraine, schizophrenia, drug or alcohol addiction and chronic fatigue syndrome.

31. A method of treating diseases or disorders associated with the 5-HT_2C receptor comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 or a composition of claim 6.

32. A method of treating diseases or disorders associated with the 5-HT_2C receptor comprising administering to a subject in need thereof a therapeutically effective amount of a compound of claim 1 in combination with one or more pharmaceutical agents.